Telecommunications systems, cable television systems, and data communication networks use optical networks to rapidly convey large amounts of information between remote points. In an optical network, information is conveyed in the form of optical signals through optical fibers. Optical fibers comprise thin strands of glass capable of transmitting the signals over long distances with very low loss. Optical networks provide higher capacity and reduced operating costs compared to traditional technologies. Fiber-optic networks may include a system of multiple network components, including switches, routers, converters, modulators, demodulators, etc.
A communications network may include one or more rack systems. A rack system includes two or more vertical posts providing a frame for mounting various components of the network system (e.g., a rack server). The rack system provides a plurality of mounting slots known as bays configured to hold a rack server and/or other network components. The rack system may allow multiple components to be stacked vertically, providing a relatively small footprint and simplifying cable connections between various components.
A network system component may include multiple electronic components housed in a chassis. A chassis may be a rectangular box or another housing that provides electronic and/or physical connections for the internal components disposed therein. For example, the chassis may include a motherboard, a midplane, a backplane, switches, routers, converters, modulators, demodulators, etc. In those systems, plug-in units (PIU) may be used to provide a variety of applications and functions. PIUs may be inserted into a chassis and coupled to a backplane or a midplane.